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Category: Versions

SQLBits Keynote Notes

Published 2022-03-10 by Kevin Feasel

Brent Ozar shares some thoughts from the first day’s keynote from SQLBits:

Pedro Lopes took the stage to talk about parameter-sensitive plan optimization, aka PSP Optimization. He demoed it with SQL Server 2022 CTP 1.3. I’ve written about this feature before, and there wasn’t anything new here in the demos. My opinion on this feature remains the same: I think it sounds like a phenomenal down payment. It won’t fix parameter sniffing, but I don’t think it’s going to backfire.

Read on for Brent’s thoughts around what Microsoft is doing for SQL Server 2022.

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Thoughts on the Long Run: PolyBase

Published 2022-03-01 by Kevin Feasel

I have some thoughts on a recent announcement:

We could see the writing on the wall here ever since Cloudera and Hortonworks merged. Cloudera Distribution of Hadoop (CDH) and Hortonworks Data Platform (HDP) were both on-premises offerings that you could also get in the cloud. Post-merger, Cloudera Data Platform (CDP) was cloud-only and, to my knowledge, they have never released an on-premises version. Cloud versus on-premises isn’t itself the issue but it does tie in with the issue: in order for PolyBase to work, certain ports need to be exposed on your Hadoop cluster. Cloud offerings tend not to want to expose a bunch of ports to internal services and so PolyBase to CDP was a non-starter.

It’s about 30% bad news, 50% good news, and 20% meh news. Click through for the longer-form version of that.

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Amazon RDS: Backups and Patching

Published 2022-02-18 by Kevin Feasel

Joey D’Antoni is not impressed:

While some services include other really useful features (for example the query data collected by the Azure SQL Database and Managed Instance platforms), I wanted to focus on the common value adds to PaaS systems across providers. I made the last two of these bold, because I feel like they are are the most important, especially in scenarios where the vendor doesn’t own the source to the applications. Like Amazon RDS for SQL Server.

Click through for Joey’s thoughts on the topic.

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The Azure SQL DB Serverless Compute Tier

Published 2022-02-10 by Kevin Feasel

Paul Randal explains why there is yet another tier of Azure SQL Database:

Over the past several years, I’ve helped numerous customers migrate SQL Server workloads to Azure SQL, including Azure SQL Database, Azure SQL Managed Instance, and Azure SQL Virtual Machines. 

In this article, I’ll explain some of the challenges of optimizing the compute cost for an Azure SQL Database deployment and review how the serverless compute tier can greatly simplify it.

Click through to see where the serverless tier fits and how you can make it work best in your environment.

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Thoughts on Upgrades

Published 2022-02-09 by Kevin Feasel

T-SQL Tuesday this month is all about upgrades, so here are a few more thoughts on the topic. Let’s start with Reitse Eskens:

Things change when you’re working with a lot of data or when you’re trying to use SQL Server to the max. At some point you’ll see new features that will support your workload or add security for your data. Here are the steps I’d take to evaluate new versions.

Todd Kleinhans tells a horror story with a happy ending:

I had just been laid off for the first time in my life from a dot com. I was a classic ASP web developer, a junior development DBA, and I knew Access and FileMaker Pro. Interviewed and got hired on as a contractor to help with Access and ASP.

Before me, a local consulting company was retained to help them with the migration from Access to SQL Server. It was a disaster.

Rob Farley thinks about ways to make the upgrade process smoother:

I don’t envy application vendors who don’t have a strong DevOps story. They need to get it in place so that they can scale, but it doesn’t happen overnight. The road to good deployment practice is long and is threatened by all kinds of things. Code coverage is rarely complete, and problems seem to find those places that don’t have good testing in place yet (typically because problems are avoided in the areas that do have good testing). All this is so much easier when a project is starting from scratch, and not the culmination of a decade or more of development needing to be compatible with the last four versions of SQL Server and Windows.

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Slow-Rolling Patches

Published 2022-02-09 by Kevin Feasel

Alex Stuart tends to end up on the late adopter side of things:

My experience of SQL upgrades is that they tend to be largely dictated by neccessity, either of the ‘the Security team is getting really twitchy about these old servers’ or ‘crap, it’s license renewal time and the vendor doesn’t support x’ variety. I’ve never performed one that wasn’t under some sort of pressure. How do we get here?

Click through for the downsides of really slow adoption. The biggest problem is that you’re trading current convenience for future pain when slow-playing adoption, as Alex mentions.

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Upgrade Strategies

Published 2022-02-08 by Kevin Feasel

Deepthi Goguri discusses upgrading:

When I started my first job as a DBA seven years ago, my project was to migrate several SQL Servers and all the servers were in SQL Server 2000. In my first SQL class at my school, I started my learning with SQL Server 2012. It was a shock to me to work on SQL 2000 databases at the time (as I am not familiar with the SQL Server 2000 yet), especially as it was my first job as a DBA.

My first project was to migrate approximately two hundred and fifty SQL 2000 SQL Servers to SQL Server 2012/2016. It took us a couple of years to successfully migrate all these Servers.

Deepthi mentions fear as a demotivating factor. In fairness, fear is a valid response to upgrades for two separate reasons: first, because the changes they release might break your existing code (something very common in the data science world); and second, because new code has new bugs that you haven’t discovered or worked around yet.

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Physical Read Double-Counting in Query Stats

Published 2022-01-28 by Kevin Feasel

David Alcock reviews the latest SQL Server 2019 cumulative update:

Microsoft recently released Cumulative Update 15 for SQL Server 2019. It contains a bunch of fixes and some improvements, I get a bit geeky with updates like this and love to have a look through the different fixes to see “Physical reads for read-ahead reads are counted incorrectly (two times) when you run queries. Therefore, the information in sys.query_store_runtime_stats and sys.dm_exec_query_stats shows incorrect values.”

Read on to see what this means and a quick test to see if it works as expected.

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The Benefits of Indirect Checkpoints

Published 2022-01-19 by Kevin Feasel

Aaron Bertrand explains why it’s probably a good idea to enable indirect checkpoints:

At Stack Overflow, the upgrade to SQL Server 2019 was not as smooth as expected. It introduced long recovery times and high CPU on a secondary, during synchronization activity after failover, patching, and network connectivity testing. This symptom wasn’t present during similar activities and workloads under SQL Server 2017.

Aaron points out that if you have databased created in older versions of SQL Server, enabling indirect checkpoints can provide a performance boost to certain activities around log writing., including backup times.

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